Draft control and regulating device



Dec.26,1939. I PowE. 2,184,399

DRAFT CONTROL AND REGULATING DEVICE Filed Sept. 26, 1956 Z SheetS-Sheet 1 w I? m 7 fig 3 g: A J

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DRAFT CONTROL AND REGULA'IING DEVICE Filed Sept. 26, 1936 2 Sheets-Sheet 2 Patented Dec. 26, 1939 UNITED STATES rATENT oF'FicE 1 Claim.

This invention relates to controlling devices, and particularly to a device adapted to be operatively related to the main steam line of a steam generator for controlling and regulating the position of dampers, draft devices or the like associated with the generator in the operation thereof.

One object of the present invention is to provide a novel construction and arrangement whereby draft devices or the like may be automatically controlled by the operation of novel means governed by changes in flow of steam in the main line of a steam generator.

More specifically, the present invention is intended to provide novel means for controlling the operation of steam generator by and in accordance with the flow of steam therefrom resulting from the reduction and increase of pressure in the main outlets, due to the demand at these points, combined, respectively, with increased and reduced velocities of the steam passing steam generator by the flow or volume of steam passing through the main steam line thereof regardless of the pressure of the steam in the generator.

Another object of the invention is to provide novel means for the operation of dampers or other draft devices, and which has a definite relation to the operation of such devices and to the amount of steam leaving the boiler for use at the'main outlets of the steam line.

' Another object of the invention is to provide novel means whereby the draft devices may be conveniently and efiiciently connected to the control device regardless of their positions relative to the connection of the control device with the steam line of a generator.

A further object of the invention is to provide a novel valve construction in the main line of a steam generator and actuated by the volume or amount of steam passing therethrough, whereby dampers and other similar draft devices are opened and closed proportionately to the volume or amount of steam passing through said main shown for illustrative purposes in the accompanying drawings, in which:

Fig. 1 is an elevational view of a steam generator, such as a furnaceboiler, or the like, illustrating the application of my improved control 6' device thereto; 7

Fig. 2 is an enlarged vertical sectional view through the operating parts of the control'device,

and taken substantially as indicated by the line 1 In Fig. 1 of the drawings, my improved Control device is shown applied to a steam generator, indicated as a whole bythe numeral 5, having a plurality of dampers or draft devices 6 and 1-- associated therewith, the'former being shown as positioned in a smoke pipe 8, and the latter as an -'20 ash pit door hingedly connected as indicated at 9 to the body of the generator 5. v The illustrative embodiment of the present inenticn as shown in the drawings comprises acasing or housing, indicated as a whole "by the numeral it, having an enlarged portion 12 intermediate its ends and having an inlet opening [3 adjacent one of its ends adapted to be connected by means of a pipe or conduit !4 to a steam dome of the generator 5,'the said casing 'being provided also with an outletop-ening 55 adjacent a side portion thereof and adapted to communicate with a pipe 16, which in conjunction with the housing ll and pipe l4 constitutesv a main steam line for conducting steam from'the generator 5 to steam outlets for various purposes as, for example, the operation of steame'ngines or the like, and for use in heating systems or for other purposes. For controlling the position of the dampers or '40 draft devices 6 and l in accordance with the amount or volume of steam passing through the main line for consumption at the outlets thereof, and in order to maintaina definite and proper relationship between the consumption of steam l at the outlets and the fuel consumed to generate additional steam, the housing I l is providedon its interior with a sleeve, indicated as a whole by the numeral ll, having a reduced lower end portion positioned in the inlet opening and provided with an inlet port l8 formedtherein com municating with the pipe l4 and having a'plurality of annularly. spaced vertically elongated outlet ports i9 formed in the wall portion of the sleeve for conducting steam, received on the, in-

terior of the sleeve II from the pipe I4, to the outlet opening I5, and thence through the pipe I6 to the steam outlets of the main line.

The outlet ports I9 are shown in the illustrative embodiment as of substantially triangular form having a base portion 2| and vertically extending side portions 22 tapered or inclined toward each other and meeting to form the apex of the triangle adjacent the upper portion of a chamber 23 formed between the enlarged portion of the housing I and the outside of the sleeve I, the total area of the outlet ports I9 being substantially equal to the cross-sectional area of the inlet port I8 formed in the lower end of the sleeve I'l.

A simple formula for determining suitable dimensions of the outlet ports I9 may be noted here as follows: Three-fourths of the diameter of the inlet port I8 divided by the number of outlet ports I9 (in the present instance, there being four in number) equals the length of the base of each outlet port, after which the substantially uniform height of the ports I 9 may be readily determined in order that the total area of the ports I9 will equal substantially the cross-sectional area of the inlet port I8 as above mentioned.

Slidably mounted in the sleeve I1 is a weighted piston, indicated as a whole by the numeral 24, and adapted to be actuated by the amount or volume of steam passing through the housing II in proportion to the reduction in pressure of the steam in the main outlets due to consumption for various purposes, the position of the piston 24 in the sleeve I! being determined by the volume or amount of steam passing through the housing regardless of the steam pressure in the generator.

For providing a balanced condition of pressure on both sides of the piston 24, it will be noted that when the piston is in the position shown I in Fig. 2 of the drawings, that steam may circulate around the sleeve I1 and through the outlet ports I 9 to the upper side of the piston, and for preventing the formation of a pocket or compression head in the upper end of the sleeve when the upper side of the piston 24 is above the upper ends of the outlet ports I9, a portion of the sleeve I1 is spaced from the casing II as shown by a plurality of grooves 25 shown, in the present instance, as formed in the outer surface of the sleeve and communicating with the interior thereof through a plurality of radially disposed notches 26 formed in the upper edge portion of the sleeve, thereby providing for a balanced condition of steam pressure on opposite sides of the piston 24 regardless of the position of the piston in the sleeve Mounted on the piston 24 and extending outwardly therefrom through a stufling box 21 mounted on a bonnet 28 secured to the upper end of the housing II is a rod or stem 29 having a cross-head 3| secured thereto adjacent the upper end thereof, the outer end portions 32 of the cross-head being positioned in vertically disposed slots 33 formed in upright guide frames 34, the said guide frames being mounted on a ring-like base portion 35 rotatably mounted in a recess 36 formed in the bonnet 28, the said ringlike base having a flange 31 extending above the upper end of the recess 35 and adapted to be engaged by the heads 38 of binding or clamping screws 39 mounted in the bonnet for securing the guide frames and base in various positions of angular adjustment with respect to the housing II and steam line I6.

Rotatably mounted on the upright guide frames 34 is a shaft 4| having a sheave 42 mounted rigidly thereon in a plane extending substantially through the stem 29 and perpendicular to the cross-arm 32, the sheave 42 being connected, in the present instance, to the cross-arm 3| by means of a flexible connector or cable 43 in a manner to rotate the shaft 4| when the stem 29 is raised by the movements of the piston 24 Within the sleeve Mounted preferably adjacent the respective outer ends of the shaft 4| in a manner to rotate therewith are a pair of sheaves 44 and 45, the sheave 44 having a flexible connector or cable 45 connected thereto adjacent one of its ends as indicated at 41, the opposite end of the cable 46 being connected to the smoke pipe damper as illustrated in Fig. 1, while the sheave 45 is provided with a flexible connector or cable 48 secured at one of its ends to the sheave 45 and at its opposite end to the draft device I shown, in the present instance, as the ash pit door of the furnace boiler. The arrangement of the structure above described is such that, as pressure is reduced at the main outlets due to the consumption of steam for various purposes, the volume of steam entering the main line through the housing II to replace the steam consumed will cause the piston 24 to rise within the sleeve I! a distance in proportion to the steam passing through the housing, and due to the connection between the piston 24 and shaft 4| through the medium of the stem 29, cross-head 3|, cable 43 and sheave 42, the shaft 4| and sheaves 44 and 45 will be rotated in a counterclockwise direction as indicated by the arrow A (Fig. 2), thereby opening the damper 6 in the smoke pipe 8 and the ash pit door 1 adjacent the bottom of the furnace boiler to provide sufiicient draft for the consumption of fuel to provide additional steam to replace that which has passed through the main outlets, the weight of the piston 24 being such that the normal position of the parts may be restored when the requirements at the main steam outlets have been supplied, it being understood that the normal tendency of the draft devices 6 and 1 is to remain, yieldingly, in closed condition.

For steadying the movements of the piston 24 within the sleeve I I under sudden changes of pressure in the main outlets and the velocity of the steam through the housing I! due to sudden changes of load, the cross-head 3| is operatively connected through a rocker arm 49 with a dash pot, indicated as a whole by the numeral 5|, positioned at the opposite side of the stem 29 from the sheave 42, the dash pot being pivotally mounted at 52 on a support 53 secured to the ring-like base 35 by means of a bolt 54. The rocker arm 49 as shown, in the present instance, comprises a tubular portion 55 pivotally connected at 56 to an upright 51 mounted on the support 53, the rocker arm 49 having a portion 58 slidably mounted in the portion 55 and pivotally connected at 59 to the cross-head 3|, the opposite end of the rocker arm 49 being connected with a dash pot piston 6| having vents or passages 62 formed therein to provide leakage from one side to another of the piston 6| during the movements thereof in the dash pot 5|.

To prevent the flow of steam in the opposite direction from the line I6, through the housing I2 and into the pipe I4, due to back pressure in the main steam line it, the reduced portion of,

the sleeve I Z is provided with a valve seat 63 surrounding the inlet port l8 and adapted to receive a valve head 64. formed on the underside of the piston 24 as clearly shown in Fig. 2 or the drawings. f

It will be observed from the foregoing description that the present invention provides a novel construction and arrangement for automatically controlling the, position of draft devices through the operation of novel means governed by changes in pressure in the main outlets combined with changes in velocity of the steam through the housing H due to such changes in pressure at the outlets, and that the operation of the de-' vice is such as to provide sufficient draft for the consumption of fuel 'to'supply sufficient steam at all times to meet the demand of the load at the main outlets.

Obviously, the present invention is not limited to the precise construction and arrangement shown and described, as the same may be various-- ly modified. Moreover, all the features of the invention need not be used conjointly, as the same may be used to advantage in variously different combinations and sub-combinations.

What I claim as new and desire to secure by Letters Patent is:

A device of the class described comprising a casing having a chamber and an outlet opening formed therein communicating with a steam line,

a bonnet secured to one end of said casing, a sleeve removably mounted in the casing and having an inlet port adjacent one of its ends adapted to communicate with a source of steam supply, a valve seat surrounding said inlet port, said sleeve having a plurality of elongated tapered outlet ports having their widest ends adjacent the lower portion thereof and communicating with the interior of said sleeve and with said chamber and outlet opening, a piston slidably,

mounted in said sleeve and having a stern exe tending outwardly through said bonnet, a portion of said sleeve adjacent the'upper end thereof having a plurality of grooves formed on its outer side communicating with said chamberto permit the passage of steam between said sleeveand casing from one side of said piston to the opposite side thereof, a valve head on said piston engageable with said valve seat, and means mounted on said bonnet adapted to be connected to a draft device and operatively connected to said stem for controlling the position of the draft device in accordance-with the position of said piston in said sleeve as determined by the 5 amount of steam passing through said casing to said steam line.

LYMAN POWELL. 

